Description du sujet de thèse

The proposed PhD program is part of the WISArD experiment: Weak Interaction Studies with 32Ar Decay. The WISArD experiment aims at testing New Physics in the electroweak sector of the particle physics Standard Model using beta decay. The angular correlation parameter aand the Fierz interference term b, which characterize beta decay are sensitive to the possible existence of exotic scalar and tensor currents. These currents are excluded from the “V-A” description of the electroweak interaction in the Standard Model, which only relies on vector and axial-vector currents. The WISArD experiment will measure these beta decay parameters down to a precision of 0.1% to be competitive with direct searches of New Physics performed at high energy at LHC.
The experiment is installed in the ISOLDE experimental hall at CERN. A first proof-of-principle data taking in 2018 validated the measurement, and allowed us to obtain the 3rd best results on a. A second data taking took place in 2021 after a full upgrade of the set-up. New modifications were implemented to constrain systematic effects to the required level of precision, and a new experimental campaign is foreseen for the end of 2023.
The PhD student will participate in the preparation and data taking of this next campaign and will analyze the data, to extract new constraints on weak scalar currents.

Contexte de travail

The PhD student will be part of the NEX group at LP2iB (Laboratoire de Physique des deux Infinis de Bordeaux). For more information, please go to: https://www.lp2ib.in2p3.fr/
The WISArD experiment is a collaboration between several institutes in different countries. The PhD student will often work with members of the collaboration, during dedicated tests and preparation of the set-up, during data-taking and meetings. Several short-term and long-term stays at CERN are also foreseen.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

The PhD applicant should have a validated M2 degree or equivalent in subatomic physics. A taste for experimental physics is better and a first experience with analysis and calculation tools such as ROOT or GEANT4 will be appreciated.